The present invention relates generally to cable hoisting systems.
For many years, it has been a conventional practice to utilize a single fastline cable hoisting system in which a deadline was connected to a fixed snubbing drum, and a wireline deflection type of weight indicator connected to the deadline.
In such a system, the current procedure, in order to obtain a faster hoisting speed for removal and replacement of sucker rods and tubing in a producing well, includes the practice of disconnecting the deadline from the fixed snubbing drum and attaching it to the main hoisting drum so as to provide a double fastline hoisting system with twice the hoisting speed of the single fastline system. This changeover is a cumbersome and time consuming operation necessitating the disconnection and reconnection of the wireline deflection indicator.
Having in mind the difficulties and inconvenience of the foregoing arrangement, the present envisions the use of a quick means for attaching and detaching the terminus end of the deadline to the snubbing drum of a conventional type weight indicator and drilling line anchor apparatus such as exemplified by the early Spalding U.S. Pat. No. 2,488,070 or the later Decker et al U.S. Pat. No. 3,973,435.
The improved cable attaching means according to the present invention increases the scope of use of the deadline anchor and weight indicating apparatus, and permits its embodiment into any one of three operating systems, as follows:
1. In which the deadline feeds from the anchor apparatus to a storage drum.
2. In which the deadline is anchored directly to the snubbing drum, the storage drum being omitted. PA1 3. In which the deadline is releasably connected to the snubbing drum so as to operate the weight indicator in a normal manner, but may be quickly detached and connected to the main hoisting drum to provide a double fastline system with double hoisting speed, during which the anchor apparatus and its weight indicating means remained inactive.